Page 159 of Rob Cook's "The Slingerland Book" states the following:
It has unfortunately beome the custom among vintage drum dealers and collectors to refer to all Slingerland solid-shell wood drums as Radio Kings and to not consider any drum a Radio King unless it has a one-piece (as opposed to plied) shell. What really distinguished the Radio King Models from other Slingerland drums were the "Radio King Brackets" which drew the tension on the snares outward rather than upward.
When the Radio King drums were introduced in 1936, the "brackets" called for a modification of the 967 strainer. The strainer with the flange out away from the drum shell for Radio King use was identified as the 967B, while the old-style 967 became known as the 967A.
The 967A would in 1948 be renamed the Rapid strainer. (It remained unchanged except the name.) It retained that name until the #673 was introduced. (To further confuse the issue, the 1955 catalog refers to a 967A as a Radio King strainer (though it's mounted on a drum without the RK brackets) and to the 967B as a Rapid Strainer.)
The upper section of the three-point strainers, which originally had been a separate piece secured by a thumbscrew so it could be swiveled down out of the way for transporting (and some playing situations), was eventually made an integral part of the strainer. The first catalog parts page to show this change was 1963, though the change was certainly made much earlier - possibly as early as the late '40's. Thee strainers were referred to (in the parts section of the 1963 catalog) as Radio King Strainers; the 967B was identified for use with the metal strap snares, while the 967A had 12 holes for gut, silk, or wire snares.
Also on page 184 of "The Slingerland Book" there is more:
The successor of the Duall as Slingerland's top-of-the-line snare drum was the Radio King. To many of today's vintage drum dealers and collectors, any Slingerland snare drum that has a solid maple shell is considered a Radio King. This is technically incorrect, as Slingerland produced other models with solid maple shells which were never marketed as Radio Kings, and sold Radio King snare drums with plied shells. (Tom toms supplied with Radio King drum outfits sported hoops engraved Radio King, though tom toms were never made with solid shells.) A better way to identify a true Radio King snare drum is the presence of the snare support brackets on both strainer and butt ends; these are part of the basis of the patent.
I don't know if that cleared it up or not. I'm under the impression if the snares extend out past the snare beds and out to brackets, it's a Radio King whether it's a single-ply or three-ply. Similar to a Rogers Dynasonic without a complete Dyna snare frame, I would think a Radio King snare with brackets, but not the proper length snare wires that extend out to the brackets, is not a "complete" Radio King. Slingerland had several snares such as Concert Kings that did not have the brackets.
So I would consider the drum in your auction a Radio King based on the snares. Funny the confusion about Radio King snares...I too am confused what constitutes a Hollywood Ace!
Dan